On Tue, Feb 16, 2010 at 01:52:02PM +0900, KOSAKI Motohiro wrote: > But this explanation is irrelevant and meaningless. CPUSET can change > restricted node dynamically. So, the tsk->mempolicy at oom time doesn't > represent the place of task's usage memory. plus, OOM_DISABLE can > always makes undesirable result. it's not special in this case. > > The fact is, both current and your heuristics have a corner case. it's > obvious. (I haven't seen corner caseless heuristics). then talking your > patch's merit doesn't help to merge the patch. The most important thing > is, we keep no regression. personally, I incline your one. but It doesn't > mean we can ignore its demerit. Yes we do need to explain the downside of the patch. It is a heuristic and we can't call either approach perfect. The fact is that even if 2 tasks are on completely disjoint memory policies and never _allocate_ from one another's nodes, you can still have one task pinning memory of the other task's node. Most shared and userspace-pinnable resources (pagecache, vfs caches and fds files sockes etc) are allocated by first-touch basically. I don't see much usage of cpusets and oom killer first hand in my experience, so I am happy to defer to others when it comes to heuristics. Just so long as we are all aware of the full story :) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>